There is by now a very extensive literature about and around the project of euthanasia of children that was initiated at Spiegelgrund by the Nazi regime, and it would create too long a digression to refer here to the material that I have relied on. However, I must take this opportunity to thank especially Friedrich Zawrel, whose childhood and youth and late, unexpected encounter with his former tormentor Heinrich Gross have inspired corresponding passages in this novel. In many interviews for books, films and lectures, as well as in conversations with me, Zawrel has given insightful and detailed accounts of what an upbringing at Spiegelgrund could be like, and this has been invaluable for my writing. I also want to thank Andrea Fredriksson-Zederbauer for all her help with research for and editing of the book, as well as for her many critical and constructive comments. Thanks also to René Chahrour and Herwig Czech, and to Werner Vogt, whose talk on 28 April 2002 at the burial in Wien’s Zentralfriedhof of the remains of the several hundreds of Spiegelgrund victims of child murder is quoted here in an abbreviated form (pp. 546–47).